Wood-screw machine



(No Model.) Q 5 Sheets-Sheet a.

W. S. DORMAN.

v WOOD SGREW MACHINE. No. 416,584. Patented Dec. 3, 1889.

lm/human lamvawko'c N. PETERS. Plwmumu m her. Wash n nnnnnn c.

(No Model.) I 5 Sheets-Sheet 4,

W.. S. DORMAN.

WOOD SCREW MACHINE.

- No. 416,584. Patented Dec. 3, 1889-.

.iiW

W. S. DORMAN. WOOD SCREW MACHINE.

No. 416,584. Patented Dec. 3, 1889.

wi/lmaowa mum,

gripping-jaws engaging a screw-blank.

UNITED STATES PATENT OFFICE.

WVILLIAM S. DORMANpOF BALTIMORE, MARYLAND.

WOOD-SCREW MACHINE.

SPECIFICATION forming part of Letters Patent No. 416,584, dated December 3, 1889.

' Application filed August 14, 1889. Serial No. 320,727. (No Model.)

To all whmn it ntay concern.-

Be it known that 1, WILLIAM S. DORMAN, a citizen of the United States of America, residing at Baltimore, in the State of Maryland, have invented new and useful Improvements in Screw-Cutting Machines, of which the following is a specification.

My invention has relation to machines for making wood -screws of that construction wherein the screw-blanks-are fed through a hollow spindle engaged by grippers as they emerge from the spindle, and gripped and cut by automatic gripping and cutting mechanism. j

The object of my invention is to simplify and improve existing mechanism used to accomplish the manufacture of screws.

My invention therefore consists in the novel construction of parts and their combination, as will be hereinafter specified and explained, and especially as the same is laid in the claims.

I have fully and clearly illustrated my invention in the accompanying drawings, wherein Figure 1 is a side view of the machine. Fig. 2 is a side view of the same, taken on reverse of illustration in'Fig. 1. Fig. 3 is a front View in elevation. Fig.4 is aplan View showing. the gearing. Fig; 5 is a central vertical section of thehollowfeed-spindle, the belt-pulley, and sliding sleeve, also showing the gripping-jaws and the means for automatically holding and dropping the blanks. Fig. 6 is a central sectional view of the lower part of the hollow spindle and the Fig. 7 is a similar view showing the grippingjaws opened and a finished screw being discharged from their grasp. Fig. 8.isabottom .view of the hollow spindle, showing the line y y of Fig. 1.

the machine, taken on the line a w of Fig. 1.

Fig. 12 is a longitudinal section taken on the Fig. 13 is a plan view of the leader-cam which gives the pitch to the threads of the screw. Fig. 14 is a plan view of the cam which operates the cuttingaw.

Fig. 15 is a plan view of the cam which operates the back-rest jaw. Fig. 16 is a detail View, partly in section, showing the arrangement of the cutting and back-rest jaws. Fig. 17 is a side view of the cutting-jaw. Fig. 18 is a side view of the back-rest jaw. Fig. 19 is an enlarged perspective of the cuttingtool. Fig. 20 is an end view of the cuttingtool. Fig. 21 is a detail plan view of the lever which moves the sleeve on the hollow spindle to open and close the gripping-jaws.

Referring to the drawings, wherein the same notations are used to designate like parts in the different figures, A design ates the supporting-frame of the machine. This can be made of such shape or parts as to properly take and hold the several elements making up the machine. I have constructed it to consist of a substantial bed-piecel, adapted to be .fixed in position to a support by any of the usual fastening means. formed seats for the cam-spindles and an aperture for the screw-pitch pin, as hereinafter specified. From the bed-pieces are projected two substantial standards 2 3, formed and connected at their upper ends with a top piece 4, which is extended back, as shown in Figs. 1 and 2, and provided with bearings from the cam-spindles. At the front of the In this bed-piece are vertical part'of. the frame are upper and lower projections 56, formed with bearings for the hollow spindle and provided with bearing-caps 7 8. At the rear of the frame is a vertically-arranged spindle 9, held in bearings 1O 11 in the frame. On the spindle 9 is mounted a horizontally-arranged cam 10*, (see Figs. 12 and 14,) which engages the rear end of the lever or bar carrying the cuttertool. This cam is irregularly stepped on its circumferential face, substantially as shown in Fig. E the drawings. The construction of this cam and its functional effects on the lever of the cutting-tool are as follows: It is designed to admit the inward movements of the rear end of the lever of the cutting-tool when not cutting the thread of the screw, and

also to operate the lever so as to give the requisite number of cutting-strokes of the tool during one revolution. To effectuate circle 12 for a distance substantially onefourth of the distance around the cam. This circular part terminates in a preliminary step 13, intended to throw the cutting-tool gradually int-o operation. The succeeding steps, designated 14, 15, and 16, respectively, representthe distance traveled during the first, second, and third cuts of the cut-tingtool, and, as shown, these steps exceed each other in height and have between them the idle steps 17 18, which permit the end of the lever of the cutting-tool to move inward and free the tool from the screw while moving vertically, as hereinafter specified.

At the termination of each of the step-surfaces 14, 15, and 16 the faces are abruptly extended, as seen at 19, which construction moves the lever and carries the cutting-tool deeper at the end of the screw-blank, and

thus tapers the end and forms the point of the screw. These projections 19 are only essentials in cutting gimlet-pointed screws, and can be dispensed with in cutting straight or machine screws. Another cam 20 is also mounted on the spindle 9 and serves to 0p crate the back-rest lever. This cam is a true circle for substantially three-fourths of its circumference, and is formed with a stepspace 21, which permits the lever to swing inward and open to that extent.

22 (see Fig. 18) designates the lever in which the back-rest is lodged, and 23 (see Fig. 17) is the lever which carries the screw-cutting tool. The back-rest lever is substantially of the shape shown in Figs. 12 and 18, having its rear portion extended straight horizontally and curved laterally, and its forward part or arm curved upward and inward and provided with a seat for the back-rest. This seat is preferably circular and is partly formed in the lever, as at 24, and partly in a cap 25, secured to the lever end, substantially as shown in Fig. 12. The back-rest 26 consists of a steel plug arranged in the seat provided for it, and is formed with a number of vertically-arranged grooves 27, in which the neck of the screw is held.

23 is the lever which carries the screw-cutting tool. It consists of a metal bar substantially straight in its horizontal direction and curved, as shown in Fig. 12, in lateral direction. In the forward end of this lever is a bit-seat 29, made to take the cutting-tool, and provided with a bit-clam p 30, by which the bit or tool is held to the lever. In the rear end of each of the levers 22 and is formed a slot 31, in which is fixed a bearing-piece 32, made adjustable by means of adjusting-screws 33. These bearing-pieces are preferably of brass or other similar material not liable to unduly wear the surface of the cams. The contact of the levers with the cams is accomplished by means of springs 34. fixed in the frame, and arranged to bear with their free ends on the levers, substantially as shown in Fig. 12 of the drawings. The lower lever, being that designated as 22, is mounted on a sleeve 35,

arranged in a hole in the bed of the machine and secured therein, and the lever 23 is fixed on the leading-bar 36 by any suitable fastening means. I have shown it as secured by a set-screw 37. Theleading-bar36l1asits lower end arranged in the sleeve 35 in the bed of the frame, and at its upper end is secured a cross-bar 38, to the ends of which are attached the lifting-springs 40 41, having their upper ends connected to the sides of the upper part of the frame, substantially as seen in Figs. 1, 2, and 3. The upper end of the lever-bar is inclined, as seen at 42, to conform to the pitch or incline of the leader or screw-pitch cam hereinafter described.

A vertically-arranged shaft 43 is suitably mounted in bearings in the frame of the machine, and thereon is fixed the leader or screwpitch cam 44. This cam is a plate arranged at a spiral incline 011 its under face in horizontal direction conforming to the pitch of the screw to be cut and to the .length of the threaded part of the screw. In the under face, which is the working-face, is a step 45, at the junction of the highest and lowest points of pressure. This cam bears with the under face on the spring-supported leaderbar, and at the start of the cut is in the position shown in Fig. 1 of the drawings, and being carried around in the direction of the arrow it pushes the leader-bar downward, contin uing the operation until the step is reached, when, by the action of the lifting-springs, the leader-bar is lifted vertically into engagement with thecam. The reciprocating movement of the leader-bar correspondingly carries the cutting-tool lever in its strokes and engagements with the screw-blank.

B denotes the hollow spindle through which the blanks are fed to the cutting mechanism. This spindle is held in the projected bearings on the front of the frame. On the spindle is fixed the driving-pulley 46, which being connected to the power by a belt (not shown) the spindle is revolved, and, through the gearing carried by it in connection with the other gearing of the machine, motion is communicated to the several elements of the mechanism. Thelower end of the spindle is enlarged in diameter, and formed with upper and lower annular collars 4.7 48, between which the lower bearing-box of the spindle is arranged. This construction and arrangement hold the spindle against vertical displacement in either direction. In the lower and enlarged part of the spindle are two vertically-arranged mortises 49 50, having their lower ends open through the end of the spindle to admit the screw-gripping jaws.

C 0' denote the screw-gripping jaws, substantially of the shape shown in the drawings in Fig. 5, and pivotally swung in the spindle on bearings 51, near their lower ends. The gripping-jaws are provided with gripping-pieces 52, arranged to meet under the end of the spindle and clamp the blank, substantially as seen in Figs. 5 and 6. At the upper ends of the gripping-jaws are adj ust-.

' ing-screws53, which set against the surface ferentsized blanks.

fected by means of springs arranged to bear them in that direction. I have shown the springs as arranged on short plugs let through the collar 47 on the spindle, and bearing with their full ends in seats formed in the back of, the gripping-jaws, as seen at 55. On the spindle B is the sliding sleeve 54, having its under face 56 inclined or rounded off rather abruptly, and at, the upper portion thereof isan annular groove 57, which is engaged by the lugs on the yoke 58 of the lever 59. This lever 59 is mounted on a fulcrum '60, arranged across and between the side steps 67 68 carry the lever upward to the surface of the cam. These steps occupy one-v fourth of the distance around the cam. WVhen the cam moves with the lever on the part 66, the sliding sleeve on the hollow spindle is lifted to its upper limit, and the gripping-jaws are wide open. Then, as the lever is raised by the stop 67, the sleeve is depressed or lowered partially and the jaws closed far enough to preventthe head of the blank falling out of their partial grip, and as the lever ascends the step 68 the jaws are closed and their full, grip exerted on the blankwhen the lever is carried to the plane of the cam.

The feed of the blanks to the action of the cutting mechanism is accomplished and regu-' 4 lated by the followingrdescribed means: The

- the spindle.

blanks are led into the bore 69 of the spindle at the top and descend by gravity until the lower one is arrested by the first stop 7 0, (see Figs. 10 and 5,) which consists of a wire of sufficient size bent into angular shape, substantially as shown, having one arm longer than the other. This is arranged in holes made transversely through the spindle in the part between the gripping-jaw seats and has a limited sliding movement therein. The long arm projects through the spindle at this part and rests with its end against the inner face of the gripping-jaw, while the short arm of the stop projects partly across the bore of A spring 71 bears with its free end on the bridge of the stopand pushes it,

so as to keep the end of the long arm lodged against the gripping-jaw, and also normally contact with one or other of the jaws.

. sixty-four of the spindle.

holds the stop, so that the short arm extends far enough across the bore of the spindle to admit the blank to continue its descent and be caught by the head, as shown in Fig. 5. Below the stop is the second stop 72, (see Fig. 9,) consisting of a straight piece of metal having its end let into a threaded hole inthe gripping-j aw and its body arranged in a hole in the spindle. This stop 72, it will be perceived, has a reversed movement across the bore of the spindle to that of the stop 70, and hence catches a blank after the upper stop, has-released it. The object will readily be perceived. The upper stop receives and holds a blank while the gripping-jaws are closed and in engagement with the neck of the screw being out, which operation being completed the jaws are opened to discharge the screw. The same movement which opens the bite of the jaws also pushes the upper stop, so that the short arm releases the head of the blank, which drops down until it is arrested by the lower stop, which has been moved inward across the bore by the inward movement of the gripping-jaw. The blank is so held until the movement of the mechanism commences to close the gripping-jaws and withdraw the stop, when the. blank dropsdown and out of the spindle, lodging with its head on the jaws,

which have not been moved at this time, so as to prevent the passage of the stem of the blank between their gripping-faces. The grip is completed after the blank is lodged, as stated.

Acrossthe face end of the spindle is secured a knock-out plate 73, having a central aperture large enough to admit the passage of the head of the blank. This plate serves to knock out the finished screws from their The grip being a strong one, the blank sometimes sticks to one or the other of the jaws, and is carried with it in opening, failing to drop; but by means of this plate the screw is freed from the jaw when it strikes the edge of the aperture, as indicated in Fig. 7 of the draw- The various elements of the machine are operated by gearing arranged on the top of the frame. On the screw-spindle is a small gear-wheel 74, meshing with a large gear-wheel 75, having its shaft in a step-bearing in the top of the machine-frame, and carrying a smaller gear-wheel 76, which meshes with a large gear 77 on the upper end of the shaft of the screwpitch cam. On this shaft, under the gear 77, is a small gear 78, which meshes wit-h a larger gear 79 on the rear cam-shaft. The gearing is proportioned so as to turn the screw-pitch cam as geared in the drawings one revolution to sixteen of the spindle, and

IIO

to revolve the rear cams one revolution to D designates the cutting-tool. This consists of a steel body formed with a beveled bit end 80 and a series of tapping-grooves 81, graduated according to the pitch of the threads of the screw, and at the lower portion is provided with a pointcut-ting bit 82, curved on its cutting-line to form the point of the screw. As any proper tool may be used in the machine, my improved cuttingbit is here only shown and generally described, because it will form the subj ect-matter of a contemporaneous and independent application for Letters Patent.

The operation is as follows: The machine being put in motion, the blanks may be supplied to the hollow spindle by any proper or known means and drop by gravity down until one of them reaches and is lodged at the first stop in the spindle, the jaws being closed to effect this object. The blank is so held until the jaws again open and the upper stop moved from across the bore of the spindle and the blank released and dropped down, to be engaged and held by the lower stop, which by the inward movement of the upper part of the gripping-jaws has been moved to pro ject partly across the bore of the spindle. The blank is thus held by the lower stop until the movements of the machine again gradually and partly close the jaws, when the blank is released and dropped to be engaged by the gap of the closing-jaws. At this condition of the mechanism the back-rest is moved into contact with the stem of the blank and the cutting-tool is brought into action by the instrumentality of the cams and pitch-bar, and engages the stem of the screw blank, which is revolved with the spindle, the pitch-cam carrying the pitch-bar down and with it the cutting-tool, thus completing one cut of the tool. The tool-holding lever by this time has reached the first idle step in the operating-cam, and is thereby freed from the screw and carried upward by the spring-actuated leader-bar and thrown again into cutting contact with the screw by the next step of the cam, and this operation repeated at the next idle step and step-surface of the cam when the circular part of the cam is reached, when simultaneously therewith the sliding sleeve is moved upward on the spindle, the cutting, mechanisms are moved apart, the gripping jaws opened, and the finished screw dropped from the machine.

Having thus described the manner of making and constructing and using my invention and explained the principle thereof and a practicable mode in which the same is applied in operation, I proceed to particularly point out and distinctly claim the parts, improvements, and combinations.

I claim as my invention as follows:

1. In a screwcutting machine, the combination of a vertically-arranged revoluble hollow screw-spindle provided with grippingjaws to hold the screw-blank, a back-rest lever mounted loosely on a vertically arranged and reciprocating shaft to reciprocate in a horizontal plane, a cutting-tool lever fixed on the vertically arranged and reciprocating shaft and arranged to reciprocate horizontally and vertically, cams to operate the said levers, and mechanism, substantially as described, for *aising and lowering the cuttingtool shaft, substantially as specified.

In a screw-cutting machine, the combination of a vertically-arranged revolving 1101- low screw-spindle formed with upper and lower annular collars 47 48 and oppositelyarranged mortises at its lower end, grippingjaws supported on fulerums in the mortises with their lower ends to close over the end of the screw-spindle, a supporting bearing-box 8 about the spindle between the said annular collars, a sliding sleeve on the hollow spindle, having a tapering lower end to engage between the upper ends of the gripping-jaws, a lever to raise and lower the sliding sleeve, and means, substantially as described, to tilt the lever, as specified.

3. In a screw-cutting machine, the combination of the revolving hollow spindle, the gripping-j aws hung thereon, and a blank-stop arranged in a hole transversely across the bore of the spindle and adapted to be engaged by one of the gripping-jaws and be moved by the movement of the gripping-jaws, substantially as described.

i. In a screw-cutting machine, the combination of the revolving hollow spindle, the grippingjaws hung thereon, and upper and lower blank-stops arranged across the bore of the spindle, substantially as described, and

for the purpose specified. V

5. In a screw-cutting machine, the combination of the revolving hollow spindle, the gripping-jaws hung thereto, an upper screwblank stop arranged across the bore of the spindle and consisting of an angular-shaped metal rod, and a lower screw-blank stop consisting of a straight metal rod arranged across the bore of the spindle, all substantially as specified.

6. The combination, with the screw-blank delivering and gripping mechanism, of the tool-holding and back-rest levers, the reciprocable leader-bar carrying the said tool-holding lever, the pitch-cam to depress the leader-bar, and springs to lift it vertically, whereby the lever of the cutting-tool is raised and lowered, substantially as described.

7. The combination, with the screw-blank delivering and gripping mechanism, of the tool-holding and back-rest levers, the leaderbar projected loosely through the back-rest lever and having the cutting-tool lever secured thereto and formed with an inclined upper end, the spirally-formed pitch-cam to depress the leader-bar, and a lifting means for the leader-bar consisting of a cross-bar secured to the upper end thereof, and springs secured to the outer ends of the cross-bar and to the frame of the machine, substantially as described.

8. In a screw-cutting machine, the combination, with the back-rest lever and the cutting-tool lever, of a cam to operate the backrest lever, and a rotating cam to operate the cutting-tool lever, said latter cam having its face formed with steps increasing successively in height, and intermediate idle steps to throw' the tool free'from engagement and into corresponding cuts on the blank, substantially as described.

9. In a screw-cutting machine, the combination, with the revolving hollow spindle and the gripping-jaws, of a' sliding sleeve on the hollow spindle, a lever to reciprocate the sliding sleeve, and a horizontally-arranged cam to operate the lever, said cam having a horizontal surface of determined distance around its circumference, a race to draw the end of p and means for opening and closing the jaws, substantially as described.

11. In a screw-cutting machine, the combination, with the vertically-arranged shaft 9, carrying the cams 1O 20, the back-rest lever, the cutting-tool lever, the leader-bar 36, having said levers pivotally arranged thereon, the shaft 43, carrying the pitch-cam 44, and the lifting-springs on the leader-bar, substantially as described, and for the purpose specified.

12. In a screw-cutting machine, the combination, with the back-rest lever and tool-holding lever, formed with slots in their rear inner ends, of adjustable bearing-pieces arranged in the slots, whereby the cut of the machine can be regulated to different-sized blanks, substantially as described.

In witness whereof I have hereunto set my hand in the presence of two attesting Witnesses.

WILLIAM S. DORMAN.

Attest:

B. W. SoMMERs, A. G. I-IEYLMAN. 

